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Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →The Omega Seamaster 120 “Big Blue” is the large, 1970s automatic chronograph identified by reference 176.004 (also written ST176.004). Its defining combination is a blue dial and bezel, angular steel case, and caliber 1040 chronograph movement. It is a distinctive vintage watch, but its size, condition, originality, and unverified water resistance matter as much as its design when considering one today.
What is the Omega Big Blue?
The Big Blue is the nickname for Omega’s Seamaster 120 automatic chronograph, reference 176.004. Auction records place examples in the early-to-mid 1970s: Phillips catalogued one as circa 1972, while Christie’s recorded a ref. ST176.004 manufactured in 1974. The “120” refers to the model’s historic depth-rating designation; it is not evidence that a surviving example remains safe to use in water.
Its visual signature is a blue dial and rotating blue bezel set in a broad, angular steel case, sometimes described as tonneau- or helmet-shaped. Chunky luminous markers and an orange-tipped central chronograph minute hand make the display conspicuous. Phillips’ catalog entry describes an Omega mesh bracelet on its particular lot, but bracelet and other components should be checked on each watch rather than assumed to be original.
What movement is in the Omega Seamaster 176.004?
The reference is associated with Omega caliber 1040, an automatic chronograph. Omega’s caliber nomenclature lists 1040 as a 22-jewel movement running at 28,800 beats per hour and introduced in 1970. The layout gives the chronograph a central minute hand, with a 12-hour register and constant seconds; the small-seconds display also integrates a 24-hour indication. The date is quickset, according to Monochrome Watches’ reference-specific account.
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- Model 212.30.44.52.01.001
There is a catalog discrepancy worth knowing: Phillips describes its circa-1972 example as having caliber 4040. In contrast, Monochrome’s reference-specific article, Christie’s lot record, and Omega’s caliber list support caliber 1040 for this family. Do not silently treat the Phillips entry as proof that all ref. 176.004 watches use 4040; if buying, ask for clear movement photographs and have the caliber checked by a qualified watchmaker.
How big is the Omega Big Blue?
It wears large and thick, and one simple diameter does not capture its irregular case shape. Published figures differ with measurement convention and source:
Rank #2
- Model 210.90.42.20.01.001
| Source | Reported dimensions | Qualification |
|---|---|---|
| Phillips | 44 mm wide, 52 mm long, 17 mm high | Dimensions for its catalogued lot; its page labels the case fields in an unusual order. |
| Monochrome Watches (2014) | 47 mm wide including crown, 52 mm long, 17 mm thick; 22 mm lug size | Width explicitly includes the crown. |
| Christie’s | 41 mm diameter | A single diameter for its 1974 lot, less descriptive of the case’s full footprint. |
Try the watch on if possible: a 52 mm length and substantial height can feel imposing, and Monochrome notes it may feel unbalanced on thinner straps. A 22 mm strap measurement is a useful starting point, not a guarantee of fit; check end shape, case clearance, buckle, and how the watch balances on your wrist.
Is the Omega Big Blue a good watch?
It can be a compelling choice if you want a large, visually distinctive vintage Omega chronograph and are prepared to evaluate a decades-old mechanical watch on its individual merits. Its bold display and unusual proportions are central to its appeal; those same dimensions may be uncomfortable or impractical for someone who prefers a compact watch. “Good” also depends on whether the example is original, in sound condition, and supported by credible service information.
Rank #3
- Omega Seamaster Automatic Chronometer Black Dial Men's Watch 210.30.42.20.01.001
Assess each component rather than relying on a seller’s overall description. Phillips’ note that its own lot was signed across case, dial, movement, and bracelet is specific to that example, not a guarantee about other watches. Specialist reporting describes aged tritium lume plots that can deform and spill material onto the dial, as well as knocks and wear to the projecting case and bezel. A seller’s claim that a watch is original or serviced is a claim to verify, not an independent inspection.
Buyer’s checklist
- Confirm the identity: Request clear photographs of the dial, case, movement, and reference markings. Where practical, have an independent watchmaker verify the reference and movement; available records do not provide a complete authentication protocol.
- Ask about originality: Establish whether the dial, hands, bezel, bracelet, and clasp are original, refinished, replaced, or later service parts. Ask for close-ups of lume plots and hands, including any staining or material transfer.
- Inspect the case and bezel: Look closely for knocks, wear, and damage around the tall case profile and projecting bezel.
- Request service details: Ask for the service receipt and what work was done. Treat “serviced” in a listing as unverified until documentation or a watchmaker’s assessment supports it.
- Check intended water use: If water exposure matters, request a recent pressure-test result and identify who performed it and when.
- Compare like with like: Consider condition, originality, service evidence, bracelet or strap completeness, seller reputation, and return terms alongside the asking price.
Can I swim with a vintage Omega Seamaster 120?
Not on the strength of its vintage “120 m/400 ft” marking or an old listing. Water resistance can change as gaskets age or after a shock, including one affecting the crown. Omega’s general care guidance says, “A watch cannot be guaranteed fully waterproof at all times,” and recommends testing water resistance annually at an authorised service centre. That is general brand guidance, not a test of any particular ref. 176.004.
Rank #4
- Model 210.22.44.51.03.001
Have the individual watch tested before exposing it to water, and follow the test provider’s advice on what that result permits. Do not operate chronograph pushers underwater: Omega’s general manual guidance cautions against this for chronographs, subject to exceptions for specified modern dive chronographs. A vintage rating does not make the Big Blue a modern dive watch.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What should I expect to pay?
There is no single current value established by the available records. Chrono24 displayed 11 reference listings, including promoted listings, when accessed; its asking prices are a changing snapshot, not completed-sale data or a market-wide census. Phillips recorded a $6,875 result for its circa-1972 lot, a historical result for that specific watch rather than a current valuation. Christie’s provides a separate 1974 lot record, not a current price guide.
Best Value
- Model 210.30.44.51.03.001
When comparing listings, match condition and originality, service documentation, dial and bezel state, bracelet or strap completeness, and seller terms. Keep asking prices separate from completed auction results; neither should be treated as a guaranteed value for another example.
Can Omega authenticate or service a Big Blue?
Omega’s vintage press-room page describes an official Certificate of Authenticity initiative for vintage timepieces, but the information available here does not establish its current price, eligibility, timing, or whether a particular ref. 176.004 qualifies. Contact Omega directly before relying on the certificate being available for a specific watch.
For care, Omega’s general guidance gives a 5-to-8-year service interval depending on model, climate, and care. That is not a reference-specific guarantee or a diagnosis of an individual watch. A watchmaker familiar with vintage chronographs can assess movement condition, while an authorised Omega service centre can advise on testing and service options.
Quick Recap
Sources and further reading
- Phillips: circa-1972 Seamaster 120 “Big Blue” auction record
- Monochrome Watches: Omega Seamaster 120 Big Blue, ref. 176.004
- Christie’s: 1974 Seamaster 120 ref. ST176.004 lot record
- Omega Museum caliber nomenclature
- Chrono24: reference 176.004 listings
- Omega user manual and general care guidance
- Omega: Certificate of Authenticity initiative for vintage timepieces
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
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